264
DOCK ENGINEERING.
Lock, can be used at any state of the tide, having a depth of 16 feet ofwater
at low water of ordinary spring tides. The basin entrance and the passage
between the basin and No. 1 Dock are each 80 feet wide. The silis are
curved, with a versed sine of 3 feet, and a central draught of 407 feet at
high water ordinary springs, and 32'3 feet at high water ordinary neaps.
Timber guiding jetties, 200 feet in length, are erected seaward of the basin
entrance, and a masonry jetty, with timber fenders, 600 feet long, leads to
the Lady Windsor Lock. This last has a length of 647 feet, a depth of 60
feet and a width of 65 feet. It is divided into two compartments by an
intermediate pair of gates. The depth at the centre of the curved sills is
52-8 feet at high water of ordinary springs, and 44'4 feet at high water of
ordinary neaps.
Eglinton Dock Entrance, Ardrossan.*
The walls of the entrance (fig. 201) were founded on rock excavated 4^
feet below the sill, which is level with the bottom of the dock and tidal
basin; the gate floor is 18 inches lower than the sill. The sluices on
Fig. 201. —Entrance to Eglinton Dock, Ardrossan.
each side of the entrance are 3 feet wide and 4 feet high, with inlet sluices,
2 feet wide and 2 feet high, at the bottom of the gate recess. The sill-
stones, hollow quoins, and sluice chamber guides are of granite, the rest are
built in rubble conerete, except the sill, gate floor, and aprons, which are of
concrète.
* Robertson on “ Ardrossan Harbour Extensions,” Min. Proc. Inst. C.E., vol. cxx.